Fault isolation is an essential network management function for optical transport networks. Optical transport networks typically employ numerous regenerators to remove noise and distortion from the signals propagating through optical networks. Regenerators may also perform signal error checking that enables sectionalization of errors in optical networks. In this scenario, faults may be isolated by checking error detection data embedded in the optical signals at each of the regenerators residing in an optical network.
However, optical transport networks are beginning to employ partial regenerators that do not perform signal error checking. Partial regenerators offer a smaller footprint and less power consumption at a lower cost than conventional regenerators, thereby resulting in an overall network cost reduction. Nevertheless, if there is a signal degradation in the network, it is still important to be able to isolate the fault within the network.
Therefore, it is desirable to provide a method for isolating faults in an optical network employing partial regenerators.